<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body id="b">
<script>
    alert('a');
    var b = prompt('请输入一个数字');
    console.log(Math.pow(b,2));
    var c = confirm('c');
</script>
<a href="http://www.baidu.com" onclick="return confirm('你确定要删除吗')">aaa</a>
</body>
</html>